Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Key Laboratory of Plant-Soil Interactions of Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Biomass Engineering Center, China Agricultural University, Beijing 100193, China.
Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Key Laboratory of Plant-Soil Interactions of Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Sci Total Environ. 2018 Apr 15;621:1512-1526. doi: 10.1016/j.scitotenv.2017.10.077. Epub 2017 Nov 6.
A sustainable management option for dealing with waste straw is to pyrolyze it to create biochar, which can then be used as a sorbent in pollution treatments, such as the recovery of phosphorus (P) from swine manure. However, the inability to directly capture soluble organic P (OP) and sparingly soluble P and the low selectivity of biochar remain key issues in this process. To overcome these, we investigated a microwave (MW) digestion pretreatment with a HFO/biochar adsorption process. The MW digestion-assisted treatment showed good performance for the solubilization of OP and sparingly soluble P. Optimized conditions (temperature=348K, time=45min, HO=3mL/30mL, HCl=0.13%) achieved an inorganic phosphorus (IP) release ratio of 83.98% and a total phosphorus (TP) release ratio of 91.83%. The P adsorption on the HFO/biochar was confirmed to follow pseudo-second-order kinetics, indicating that the P adsorption process was mainly controlled by chemical processes. The Freundlich model offered the best fit to the experimental data. The maximum amount of P adsorbed on HFO/biochar was in the range of 51.71-56.15mg/g. Thermodynamic calculations showed that the P adsorption process was exothermic, spontaneous, and increased the disorder in the system. Saturated adsorbed HFO/biochar was able to continually release P and was most suitable for use in an alkaline soil. The amount of P released from saturated adsorbed HFO/biochar reached 8.16mg/g after five interval extractions. A P mass balance indicated that 8.76% of the TP was available after the solubilization, capture, and recovery processes.
处理秸秆废弃物的可持续管理选择是将其热解制成生物炭，然后将其用作污染处理中的吸附剂，例如从猪粪中回收磷（P）。然而，生物炭无法直接捕获可溶有机磷（OP）和难溶磷，且选择性低，这仍然是该过程中的关键问题。为了克服这些问题，我们研究了一种微波（MW）消化预处理与 HFO/生物炭吸附工艺相结合的方法。MW 消化辅助处理在溶解 OP 和难溶磷方面表现出良好的性能。优化条件（温度=348K，时间=45min，H2O=3mL/30mL，HCl=0.13%）可实现无机磷（IP）释放率 83.98%和总磷（TP）释放率 91.83%。HFO/生物炭对 P 的吸附符合准二级动力学，表明 P 的吸附过程主要受化学过程控制。Freundlich 模型对实验数据拟合度最好。HFO/生物炭对 P 的最大吸附量在 51.71-56.15mg/g 范围内。热力学计算表明，P 的吸附过程是放热的、自发的，并增加了系统的无序度。饱和吸附的 HFO/生物炭能够持续释放 P，最适合用于碱性土壤。饱和吸附的 HFO/生物炭在五次间隔提取后，可释放出 8.16mg/g 的 P。磷质量平衡表明，在溶解、捕获和回收过程后，8.76%的 TP 是可用的。
